Plate type refrigerant evaporator



Oct. 30, 1951 Filed Jan. 3, 1947 T. O. LESTER PLATE TYPE REFRIGERANTEVAPORATOR 2 SHEETS-SHEET l /NVENTOR Thomas O. LesTer ATTORNEY 0611. 30,195] Q LESTER 2,573,583

' PLATE TYPE REFRIGERANT EVAPORATOR Filed Jan. 3, 1947 2 VSHEETSS;-IEET2 Q J 27 l;

27 F|G.4. 5 I FIG.5.

FIG.6.

' 'INVENTOR Thomas O. Les-rer ZZ/WW W ATTORNEY Patented Oct. 30, 1951OFFICE PLATE TYPE REFRIGERANT EVAPORATOR Thomas 0. Lester, Downers GroveTownship, Du Page County, 111., assignor to Kold-Hold Manufacturing00.,v Lansing, Mich., a'coi'poration of Michigan Application January 3,1947, Serial No. 720,128

3 Claims.

This invention relates to heat exchangers and more particularly toheatexchangers of the socalled plate type. v

The principal object of the invention is to provide a heat exchangeplate of particularly simple and economical construction.

Another object is to provide a heat exchange plate in which passagewaysfor fluid are defined in part by rods bent'into serpentine form.

These objects will more fully appear in the following specification whenread in connection with the accompanying drawings, wherein:

Figure 1 is a plan view of an evaporator plate embodying the invention;

Figure 2 is a cross-sectional view taken on substantially the line 2'2of Figure 1;

Figure 3 is a plan view of one side wall of the evaporator with a pairof serpentine rods in place thereon;

Figure 4 is a 'plan view of a modified formof heat exchanger embodyingthe invention;

Figure 5 is a cross-sectional view taken on substantially the line 5-5of Figure 4' and Figure 6 is a plan view of the heat exchanger with onewall thereof removed.

The invention is shown in Figures 1 to 3 as embodied in a refrigerantevaporator of the socalled hold-over plate type, but it will be evidentthat the invention is not limited to evaporators of this type, nor everto evaporators, but may be utilized either in heating or coolingsystems.

The evaporator illustrated in Figures 1 to 3 includes a container Iformed from two sheet metal side walls II and I2. Side wall II ispressed into a shallow dish shape. A flange I3 surrounds the perimeterof the side wall II. The openings are formed in the ends of side wall IIto receive a pair of couplings I4 and I as will more fully appearpresently. Filler openings closed by a removable threaded plug I5 arealso formed in side wall II adjacent opposite corners thereof.

Side wall I2 is flat and of the same size as side wall II. The two sideWalls are seam welded about their perimeters in the region of the flangePassageways for refrigerant are formed in the container ID by means of apair of rods I1 and I8. The rods are preferably copper clad steel. Theyare bent into similar serpentine configuration as shown in Figure 3, sothat when arranged as shown they are spaced equidistantly throughouttheir linear extents.

The two bars are arranged as shown and the couplings I4 and I5 arebrazed or otherwise secured to each pair of adjoining ends. The ends ofthe couplings I4 and I5 adjacent the rods I1 and I8 are of the samethickness as the diam* eter of the rods I1 and I8 so as to fit tightlyagainst the side walls II and I2. Preferably the couplings are copperclad also.

One surface of the side wall I2 is coated with a suitable flux and therods I! and I8 are laid upon the fiuxed' surface in the position. shownin Figure 3'and ftacked thereto by brazing or soldering. The side wallII is then coated with flux on its inner surface and placed over therods I I and I8 and side wall I2. The couplings I4 and I5 are insertedin the openings in the wall I] adapted to receive them.

The two side walls II and I2 are clamped firmly in position, pressurebeing applied in. such a manner as to bring the inner surfaces of theside walls into contact with the rods IT and I8. Heat is then applied tofuse the copper coating of the rods to the inner surfaces of the sideWalls. The edges of the side walls are seam-welded togetherasmentionedvabove. The welding may be done either before or after brazingthe rods to the side walls.

From the foregoing it will be seen that a serpentine passageway I9 isformed between the rods I1 and I8 extending from coupling I4 to couplingI5. The space within the container I0 outside of the passageway I9 isfilled with a suitable eutectic solution through the filler holes, andthe latter are then closed by plugs I6.

Couplings I 4 and I5 may be connected to a refrigeration system of thecompressor-condenser type and refrigerant passed through the passagewayI9 to solidify the eutectic solution. The connections may be permanent,as in a fixed installation, or may be disconnected when the plate isemployed in a movable refrigerating unit such as a truck or railway car.

Instead of using copper clad rods and couplings corrosion resistantsteel without coating may be employed. In that case, then sheets ofbrazing metal are placed between the rods and the side walls prior tobrazing.

Figures 4 to 6 illustrate a modified form of the invention. It comprisesa container 20 comprising a pairof Walls 2| and 22 spaced apart by bars23, 24 and 25 positioned between the walls 2I and 22.

The walls 2| and 22 are flat sheets of metal of generally rectangularshape, the corners of which preferably are rounded as shown. Wall 2I isprovided with two drawnecks 26 and 21 for a purpose which will presentlyappear.

Preferably, although not necessarily, the bars 23, 24 and 25 are ofrectangular cross-section, and are all of equal thickness. The bar 23 isbent to conform to the shape of the perimeters of the walls 2| and 22.The two ends of the bar 23 are arranged in abutting relation and arebrazed or welded together at28. 1 v

The bars 24 and 25 are all of equal length and are somewhat shorter thanthe lengths of the walls 2| and 22. The bars 24 and 25 are arranged uponthe wall 22, asshown in Figure 6, H

with the bars 24 abutting the bar 23 at the left hand end of the heatexchanger (as viewed in- V Figure 6), and the bars 25 abutting the bar"23 at the other end of the heat exchanger. The wall 2| is then laidupon the bars 23, 24 and 25 and the assembly clampedrtogether after.

which they are joined together by brazing or welding.

If the bars are to be brazed to the walls 2| and 22, either the barsmust be copper clad, or brazing metal must beplaced between the bars andthe walls, as in the case of the modification previously described. Onthe other hand, the bars may be welded to the walls after'assembly ofthe parts in the manner described.

It will be apparent from the foregoing that the walls 2| and Hand thebar 23 form a container having inlet and outlet ports at the drawnecks26 and 21. Within the container is a serpentine passageway for fluid,formed by the walls and the bars 24 and 25.

L From the foregoing it will be seen that the present invention providesa novel heat exchanger of very simpleand economical construction.

.The scope of the invention is indicated in the appended'claim's. 9

II la 1 V '-'1..A' hold-over evaporator comprising a con-, tainer'formed from a pair of spaced apart side walls joined together in fluidtight engagement throughout'their perimeters, a pair of elongated rodsof serpentine shape between said side walls, said rods being of similarshape and spaced apart throughout their linear extents, each of saidrods said side walls throughout the linear extents of said rods.

3. A 'heat exchanger comprising a container including a pair ofrelatively closely spaced parallel side walls, means joining said sideWalls together in fluid tight engagement throughout their perimeters, .apair of elongated rods of generally similar serpentine shape arranged inspaced relation between said side walls and united to said side wallsthroughout the linear extents of said rods, said rods cooperatingwithsaid side walls to provide a serpentine passageway for fluid and spacesoutside of said passage,- way for a eutectic solution, and means on saidcontainer for coupling the. ends of said passage way to a fluidcirculating system.

THOMAS O. LESTER.

REFERENCES CITED The following references, are of record in the file ofthis patent? UNITED STATES P ATENTS

